Update to 6.31 or 6.35 OFW then use the minna no sukkuri exploit with Half Byte Loader/HEN and Prometheus iso loader (all is on the news on this very site).
Not only that works on any PSP, it also allows you to boot all current games without need to hack the isos.
GEN is too buggy (and outdated in line with SONY OFW) and sometimes it even makes the person frustrated with games crashing.
Now, to use "advanced" things like plugins you should use CFW and for stability reasons I recommend 5.00 M33. Using such a old FW with newer games requires hacking the game ISOs though.
Definitely if you aim for ease of use, go with 6.35 with game exploit + HBL/HEN and Prometheus ISO loader.
A good thing about having such a old PSP is that you can toss pandora at it anytime so updating to lattest SONY OFW will never get you stuck.
SCPH-10000_GH-001 SCPH-15000_GH-003 SCPH-18000_GH-008 SCPH-30001_GH-005 SCPH-30000_GH-016(V4) SCPH-30001_GH-010(V4)
2xSCPH-10190, 2xSCPH-10350, 2xSCPH-10280
"**** j0 hackers!"
-Sjeep (As seen on TOXIC OS ELF...)